SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd5194075fbf184ba1135ccca423b67cf2eac44d8d4ae39aa990c12b0a73f45d' 
  AND token = 'vd+R7tZKSKrWECg/IZjpicKvjwZkix5WkVviIhD6Qzo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}